1. Field of the Invention
The present invention relates to an external wall construction comprising a bearing wall constituted by fixing a plurality of ceramic type external wall panels to a building framework of a building through framework wall construction methods or skeleton framing wall construction methods.
2. Description of the Related Arts
Conventional external wall constructions for building structural panels are known to be external wall constructions that are constructed through framework wall construction methods or skeleton framing wall construction methods.
An example of such a conventional external wall construction 9 is illustrated in FIG. 19.
This external wall construction 9 includes a building framework 92 constituted of framing materials 921 such as squared logs, building structural panels 93 fixed on the building framework 92, waterproof sheets 94 set on the building structural panel 93, lateral furring strips 95 fixed on the building structural panels 93 with the waterproof sheets 94, and external wall panels 96 for example ceramic type panels fixed on the building structural panels 93 with the lateral furring strips 95 (see FIGS. 19 and 20).
The building structural panels 93 are unified with the building framework 92 to form a bearing wall 930 which resist the vertical or horizontal pressure, and thus a security of constructional bearing strength is secured.
The constructing process of this external wall construction 9 includes framing the building framework 92 with the framing materials 921 in the first step, fixing the building panels 93 by face-nailing nails 935 on the building framework 92 in the second step (As a result, bearing wall 930 is formed.), fixing lateral furring strips 95 on the building structural panels 93 interposing the waterproof sheets 94 by nailing in the third step, and fixing the external wall panels 96 for example ceramic type panels on the building structural panels 93 interposing the lateral furring strips 95 by nailing in the fourth step.
A coating material is applied to a front surface of the external wall panels 96 as necessary.
In this manner, the external wall construction 9 can be obtained.
However, such a conventional external wall construction 9 presents following drawbacks.
The aforementioned external wall construction 9 has many components i.e. the building framework 92, the building structural panels 93, the waterproof sheets 94, the lateral furring strips 95, and the external wall panels 96. Consequently the construction is extremely complicated (see FIGS. 19 and 20).
And the complicated construction causes requirements of many construction steps and also leads to increased material costs.
And the aforementioned external wall construction 9 except for the building framework portion is so thick that effective indoor spaces are reduced.
It would be thinkable to fix the external wall panels 96 directly to the building framework 92 through face-nailing with the furring strips 95 being interposed therebetween. However, in case the external wall panel is ceramic type, cracks 966 or chippings 967 are apt to be generated through face-nailing in peripheries of portions at which nails 935 pierce through rearward surfaces 961 of the panels as illustrated in FIG. 21 since the external wall panels 96 do not exhibit particular shock-resistant characteristics. Consequently, fixing force of the external wall panels 96 to the building framework 92 will be degraded and may cause leakage of water.
While it is possible to prevent penetration of water into the interior of the building (arrow B in FIG. 20) by the provision of the waterproof sheets 94 in the external wall construction 9, absorption of water of the external wall panels 96 themselves from their rearward surfaces 961 cannot be prevented.
So, generally, the rearward surfaces 961 of the external wall panel 96 is coated by sealer, but the treatment is still insufficient to prevent absorption of water. As a result absorption of water may occur particularly through the cracks 966 or chippings 967. Such absorption of water may cause dimensional changes in the external wall panels 96. Moreover, if carbon dioxide penetrates through portions of the cracks 966 or chippings 967, carbonation or neutralization of external wall panels 96 through aging may be promoted and may lead to deterioration in durability.
There is a drawback that preventing condensation on indoor surfaces of the external wall panels 96 or building framework 92 may become difficult when the external wall panels 96 is directly fixed to the building framework 92.
More particularly, when the external wall panels 96 is directly fixed to the building framework 92 as illustrated in FIG. 24(A), heat insulators 98 are formed on indoor sides of the external wall panels 96. Particularly during wintertime, air 7 of high temperature and humidity residing indoors passes through the heat insulators 98 and reaches the interior of the external wall panels 96. The temperature of the proximity to the external wall panels 96 is low during wintertime, since it is close to outside-air temperature. Thus, the air 7 of high temperature and humidity passing from indoors through the heat insulators 98 is cooled to result in condensation on inner surfaces of the external wall panels 96, the heat insulators 98, and the surface of the building framework 92.
In an arrangement in which the building structural panels 93 are fixed to the building framework 92 and in which the external wall panels 96 are constructed with the lateral furring strips 95 being interposed therebetween as illustrated in FIG. 20, it is possible to provide ventilation layers 97 between the building structural panels 93 and the external wall panels 96 (see FIG. 23).
More particularly, the ventilation layers 97 are provided in the following manner. When the external wall panels 96 is constructed through horizontal siding work, the vertical furring strips 950 are constructed in longitudinal directions as illustrated in FIG. 22 (A), and when the external wall panels 96 is constructed through vertical siding work, the lateral furring strips 95 are formed on notches 951 and are constructed in vertical directions as illustrated in FIG. 22(B).
With this arrangement, it is possible to obtain ventilation layers 97 wherein air 7 residing between the external wall panels 96 and the building structural panels 93 is reliably released upward. Generation of condensation as explained above can be accordingly prevented since air 7 passes through the ventilation layer 97 as illustrated in FIG. 23. Note that reference numeral 928 in FIGS. 22(A), 22(B) denotes a window frame.
However, the ventilation layer 97 cannot be provided in case the external wall panels 96 are directly fixed to the building framework 92 (see FIG. 24(A)). Since girths 924 of the building framework 92 intercept spaces formed between right and left continuous columns 923 as illustrated in FIG. 24 (B), the passage of air 7 of high temperature and humidity for upward release is blocked thereby (see FIG. 24(A)).
Condensation may be accordingly generated on the external wall panels 96, heat insulators 98 or the building framework 92, which may lead to degradations of durability of the bearing wall owing to corrosion of the building framework 92 or degradations of heat-insulating performance owing to swelling of the heat insulators 98. Penetration of moisture into the interior of the external wall panels 96 will cause gradual degradation of the durability of the panels themselves, and may also cause corrosion of timbers in case the building framework is comprised of timbers.
The present invention has been made in view of the above problems of the related art, and it is an object of the invention to provide an external wall construction improving workability, waterproof properties, durability and ventilating properties of a bearing wall.
The present invention relates to an external wall construction comprising a building framework of a building and a bearing wall constituted with a plurality of ceramic type external wall panels to be fixed to the building framework, wherein the external wall panels are formed by backing resin sheets on rearward surfaces thereof, and wherein waterproof tapes are interposed between the external wall panels and the building framework.
As explained above, the external wall construction comprises the building framework and the plurality of external wall panels. Thus the external wall construction is simple arrangement and may be easy to be constructed. Decreases in material costs can also be achieved due to the small number of constituents.
Further, since the external wall panels are formed by backing resin sheets on rearward surfaces thereof, water or carbon dioxide will not be absorbed from the rearward surfaces. Accordingly, dimensional changes in the external wall panels can be prevented, and carbonation or neutralization will not be promoted. It is thereby possible to obtain an external wall construction having superior durability.
The provision of resin sheets backed to the external wall panels further serves to prevent generation of cracks or chippings when the panels is face-nailed to the building framework.
Waterproof tapes are interposed between the external wall panels and the building framework. More particularly, the waterproof tapes are interposed between the resin sheets backed on the rearward surfaces of the external wall panels and the framing materials constituting the building framework.
In this manner, penetration of water from between the external wall panels and the building framework can be reliably prevented.
It has also been enabled this arrangement to omit a separate step for constructing the waterproof sheets as it had been necessary in conventional structures for constructing exterior walls, and to thereby achieve further simplification of the external wall construction, and moreover, further simplification of construction.
As explained above, it is possible to provide an external wall construction improving workability, waterproof properties, durability, and ventilating properties of a bearing wall.